Manufacturing Technology Today

R. Raghunath ¹, N. Ramakrishna Reddy ¹, Ceena Sunil ¹, Narahari Datta ¹, B. Sambasiva Rao ¹, P. V. Murali ², Venugopal ²

Affiliations
1 ISTRAC, Indian Space Research Organization, Bangalore, IN
2 ECIL, Hyderabad, IN

Abstract

ISRO ambitious program "Chandrayaan mission" initiated the establishment of a ground station for Telemetry and Tracking of chandrayaan satellite. The ground station was configured with a 32 meter antenna system capable to meet chandrayaan mission and also having capability of telemetry and tracking deep space objects. The antenna system is designed, manufactured, tested and successfully installed at Byalallu village near Bangalore with public and private industrial participation. One of the major challenges in this project was to realize a reflector of 32 meter diameter in size having a profile accuracy of 0.3mm rms. The challenge was in terms of manufacturing and measurement techniques used to measure with close tolerances of large surface area. This paper deals with the measurement techniques of antenna reflector surface using a laser tracker instrument.

Full Text

     

B. Sambasiva Rao ¹, K. C. Navada ¹, Ceena Sunil ¹

Affiliations
1 ISTRAC, Indian Space Research Organization, Bangalore, IN

Abstract

The important parameter for precision tracking radar mount is the requirement of very high pointing accuracy. The overall mechanical pointing accuracy aimed is of 13 arc-seconds. The major subsystems of radar mount hardware are azimuth housing, elevation module, yoke arms & intermediate frame. Non orthogonality or the deviation in perpendicularity between the azimuth and Elevation axis is one of the major contributing factor for the pointing accuracy. The detailed machining process, inspection during machining, limiting factors and subsequent inspection of critical parameters of mount are worked out for various stages for achieving a high order orthogonality. The elevation module houses an azimuth slewing ring bearing (SRB) in the vertical axis and two elevation slewing ring bearings on the horizontal axis. The non orthogonality error is contributed by the concentricity and co planarity of the two elevation bearing axis with respect to the vertical bearing axis.

Full Text